Question

The normals at three points $P,Q,R$ of the parabola $y^2=4ax$ meet in $(h,k)$, the centroid of triangle $PQR$ lies on

• A. $y=-a$
• B. $x=a$
• C. $y=0$
• D. $x=0$

Answer 1

The correct option is C $y=0$

The centroid of the triangle formed by the cornomal points lies on the axis of the parabola.
So we can conclude that the centroid of $\Delta PQR$ must lie on $y=0$ or x-axis or the axis of parabola $y^2=4ax.$